Julio Alberdi is a marketing analyst and made $28,000 last year. He paid $5,000 in taxes, and spent another $10,000 for food, housing, a car, and other "necessities." Julio's discretionary income was:
A) $28,000
B) $13,000
C) $23,000
D) $18,000
E) There is not enough information to tell.
Answer: B